The club were unable to reach an agreement with the former Cork City winger, who was their top-scorer with 12 goals this season.

He will now leave on a free transfer.

Sadlier, 25, was named in two of Mick McCarthy's provisional Republic of Ireland squads last year and will be hoping for a move to a higher division to press his case for inclusion under Stephen Kenny.

Donegal defender Shane Blaney, 21, will also leave Doncaster after reaching the end of his contract.